mmse_g.m

用matlab编的语音增强的一个程序

function y=mmse_g(x,n)
%this function complete speech enhancement with mmse ;
% n is the number of a speech frame;
%clear;

sample=n; 
a=0.6;
b=5;
%[y,fs,bit]=wavread('G:\5.wav');
N=ceil(length(x)/sample);
noise=prepower(x,15,sample,2);
j=N*sample;
for k=1:sample,
   if(j>length(x)),
   x(j)=0;
   j=j-1;
   end;
end;
state=0;
for k=1:N-1,
   for n=1:sample,
      z(n)=x((k-1)*sample+n);
   end;
   Y=fft(z,sample);
   phase=angle(Y);
   Y=sum2(Y,2);
   r=Y/noise;
   if(state>0),
      r_e=max((1-a)*r/b+a*r_e_last,1+0.005);
      
   else 
      r_e=max((1-a)*r/b,1+0.005);
   end;
   u_e=r_e-1;
   r_e_last=r_e;
   state=state+1;
   u_e=u_e./(1+u_e);
   A=u_e.*(Y.^0.5);
   S=A.*exp(i*phase);
   s((k-1)*sample+1:((k-1)*sample+sample))=ifft(S,sample);
end;
y=s;
%wavwrite(s,fs,bit,'G:\9.wav');